Activate Virtualization On Demand

Message ID	1237279648-7839-1-git-send-email-agraf@suse.de (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n2H8lXio032282 for <patchwork-kvm@patchwork.kernel.org>; Tue, 17 Mar 2009 08:47:33 GMT From: Alexander Graf <agraf@suse.de> To: kvm@vger.kernel.org Subject: [PATCH] Activate Virtualization On Demand Date: Tue, 17 Mar 2009 09:47:28 +0100 Message-Id: <1237279648-7839-1-git-send-email-agraf@suse.de> Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index c25347f..df6bab1 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -124,7 +124,7 @@ long ia64_pal_vp_create(u64 *vpd, u64 *host_iva, u64 *opt_handler) static DEFINE_SPINLOCK(vp_lock); -void kvm_arch_hardware_enable(void *garbage) +int kvm_arch_hardware_enable(void *garbage) { long status; long tmp_base; @@ -137,7 +137,7 @@ void kvm_arch_hardware_enable(void *garbage) slot = ia64_itr_entry(0x3, KVM_VMM_BASE, pte, KVM_VMM_SHIFT); local_irq_restore(saved_psr); if (slot < 0) - return; + return -EINVAL; spin_lock(&vp_lock); status = ia64_pal_vp_init_env(kvm_vsa_base ? @@ -145,7 +145,7 @@ void kvm_arch_hardware_enable(void *garbage) __pa(kvm_vm_buffer), KVM_VM_BUFFER_BASE, &tmp_base); if (status != 0) { printk(KERN_WARNING"kvm: Failed to Enable VT Support!!!!\n"); - return ; + return -EINVAL; } if (!kvm_vsa_base) { @@ -154,6 +154,8 @@ void kvm_arch_hardware_enable(void *garbage) } spin_unlock(&vp_lock); ia64_ptr_entry(0x3, slot); + + return 0; } void kvm_arch_hardware_disable(void *garbage) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 9057335..6558ab7 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -80,7 +80,7 @@ int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu) return r; } -void kvm_arch_hardware_enable(void *garbage) +int kvm_arch_hardware_enable(void *garbage) { } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index cbfe91e..a14e676 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -70,7 +70,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { /* Section: not file related */ -void kvm_arch_hardware_enable(void *garbage) +int kvm_arch_hardware_enable(void *garbage) { /* every s390 is virtualization enabled ;-) */ } diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4627627..72d5075 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -463,7 +463,7 @@ struct descriptor_table { struct kvm_x86_ops { int (*cpu_has_kvm_support)(void); /* __init */ int (*disabled_by_bios)(void); /* __init */ - void (*hardware_enable)(void *dummy); /* __init */ + int (*hardware_enable)(void *dummy); void (*hardware_disable)(void *dummy); void (*check_processor_compatibility)(void *rtn); int (*hardware_setup)(void); /* __init */ diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1821c20..06aeb7f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -262,7 +262,7 @@ static void svm_hardware_disable(void *garbage) cpu_svm_disable(); } -static void svm_hardware_enable(void *garbage) +static int svm_hardware_enable(void *garbage) { struct svm_cpu_data *svm_data; @@ -271,16 +271,20 @@ static void svm_hardware_enable(void *garbage) struct desc_struct *gdt; int me = raw_smp_processor_id(); + rdmsrl(MSR_EFER, efer); + if (efer & EFER_SVME) + return -EBUSY; + if (!has_svm()) { printk(KERN_ERR "svm_cpu_init: err EOPNOTSUPP on %d\n", me); - return; + return -EINVAL; } svm_data = per_cpu(svm_data, me); if (!svm_data) { printk(KERN_ERR "svm_cpu_init: svm_data is NULL on %d\n", me); - return; + return -EINVAL; } svm_data->asid_generation = 1; @@ -291,11 +295,12 @@ static void svm_hardware_enable(void *garbage) gdt = (struct desc_struct *)gdt_descr.address; svm_data->tss_desc = (struct kvm_ldttss_desc *)(gdt + GDT_ENTRY_TSS); - rdmsrl(MSR_EFER, efer); wrmsrl(MSR_EFER, efer | EFER_SVME); wrmsrl(MSR_VM_HSAVE_PA, page_to_pfn(svm_data->save_area) << PAGE_SHIFT); + + return 0; } static void svm_cpu_uninit(int cpu) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5cf28df..b40ca0d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1068,12 +1068,15 @@ static __init int vmx_disabled_by_bios(void) /* locked but not enabled */ } -static void hardware_enable(void *garbage) +static int hardware_enable(void *garbage) { int cpu = raw_smp_processor_id(); u64 phys_addr = __pa(per_cpu(vmxarea, cpu)); u64 old; + if (read_cr4() & X86_CR4_VMXE) + return -EBUSY; + INIT_LIST_HEAD(&per_cpu(vcpus_on_cpu, cpu)); rdmsrl(MSR_IA32_FEATURE_CONTROL, old); if ((old & (FEATURE_CONTROL_LOCKED | @@ -1088,6 +1091,8 @@ static void hardware_enable(void *garbage) asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr) : "memory", "cc"); + + return 0; } static void vmclear_local_vcpus(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2ea8262..1fd716d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4220,9 +4220,9 @@ int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu) return kvm_x86_ops->vcpu_reset(vcpu); } -void kvm_arch_hardware_enable(void *garbage) +int kvm_arch_hardware_enable(void *garbage) { - kvm_x86_ops->hardware_enable(garbage); + return kvm_x86_ops->hardware_enable(garbage); } void kvm_arch_hardware_disable(void *garbage) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 11eb702..7678995 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -292,7 +292,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu); void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu); int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu); -void kvm_arch_hardware_enable(void *garbage); +int kvm_arch_hardware_enable(void *garbage); void kvm_arch_hardware_disable(void *garbage); int kvm_arch_hardware_setup(void); void kvm_arch_hardware_unsetup(void); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 68b217e..7c40743 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -65,6 +65,8 @@ DEFINE_SPINLOCK(kvm_lock); LIST_HEAD(vm_list); static cpumask_var_t cpus_hardware_enabled; +static int kvm_usage_count = 0; +static DEFINE_SPINLOCK(kvm_usage_lock); struct kmem_cache *kvm_vcpu_cache; EXPORT_SYMBOL_GPL(kvm_vcpu_cache); @@ -75,6 +77,8 @@ struct dentry *kvm_debugfs_dir; static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); +static int hardware_enable_all(void); +static void hardware_disable_all(void); static bool kvm_rebooting; @@ -931,6 +935,7 @@ static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { static struct kvm *kvm_create_vm(void) { + int r = 0; struct kvm *kvm = kvm_arch_create_vm(); #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET struct page *page; @@ -938,6 +943,11 @@ static struct kvm *kvm_create_vm(void) if (IS_ERR(kvm)) goto out; + + r = hardware_enable_all(); + if (r) + goto out_err; + #ifdef CONFIG_HAVE_KVM_IRQCHIP INIT_LIST_HEAD(&kvm->irq_routing); INIT_HLIST_HEAD(&kvm->mask_notifier_list); @@ -946,8 +956,8 @@ static struct kvm *kvm_create_vm(void) #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET page = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!page) { - kfree(kvm); - return ERR_PTR(-ENOMEM); + r = -ENOMEM; + goto out_err; } kvm->coalesced_mmio_ring = (struct kvm_coalesced_mmio_ring *)page_address(page); @@ -955,15 +965,13 @@ static struct kvm *kvm_create_vm(void) #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) { - int err; kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops; - err = mmu_notifier_register(&kvm->mmu_notifier, current->mm); - if (err) { + r = mmu_notifier_register(&kvm->mmu_notifier, current->mm); + if (r) { #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET put_page(page); #endif - kfree(kvm); - return ERR_PTR(err); + goto out_err; } } #endif @@ -984,6 +992,11 @@ static struct kvm *kvm_create_vm(void) #endif out: return kvm; + +out_err: + hardware_disable_all(); + kfree(kvm); + return ERR_PTR(r); } /* @@ -1034,6 +1047,7 @@ static void kvm_destroy_vm(struct kvm *kvm) mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); #endif kvm_arch_destroy_vm(kvm); + hardware_disable_all(); mmdrop(mm); } @@ -2327,14 +2341,40 @@ static struct miscdevice kvm_dev = { &kvm_chardev_ops, }; -static void hardware_enable(void *junk) +static void hardware_enable(void *_r) { int cpu = raw_smp_processor_id(); + int r; + + /* If enabling a previous CPU failed already, let's not continue */ + if (_r && *((int*)_r)) + return; if (cpumask_test_cpu(cpu, cpus_hardware_enabled)) return; + r = kvm_arch_hardware_enable(NULL); + if (_r) + *((int*)_r) = r; + if (r) { + printk(KERN_INFO "kvm: enabling virtualization on " + "CPU%d failed\n", cpu); + return; + } + cpumask_set_cpu(cpu, cpus_hardware_enabled); - kvm_arch_hardware_enable(NULL); +} + +static int hardware_enable_all(void) +{ + int r = 0; + + spin_lock(&kvm_usage_lock); + kvm_usage_count++; + if (kvm_usage_count == 1) + on_each_cpu(hardware_enable, &r, 1); + spin_unlock(&kvm_usage_lock); + + return r; } static void hardware_disable(void *junk) @@ -2347,6 +2387,18 @@ static void hardware_disable(void *junk) kvm_arch_hardware_disable(NULL); } +static void hardware_disable_all(void) +{ + if (!kvm_usage_count) + return; + + spin_lock(&kvm_usage_lock); + kvm_usage_count--; + if (!kvm_usage_count) + on_each_cpu(hardware_disable, NULL, 1); + spin_unlock(&kvm_usage_lock); +} + static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, void *v) { @@ -2594,7 +2646,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size, goto out_free_1; } - on_each_cpu(hardware_enable, NULL, 1); r = register_cpu_notifier(&kvm_cpu_notifier); if (r) goto out_free_2; @@ -2642,7 +2693,6 @@ out_free_3: unregister_reboot_notifier(&kvm_reboot_notifier); unregister_cpu_notifier(&kvm_cpu_notifier); out_free_2: - on_each_cpu(hardware_disable, NULL, 1); out_free_1: kvm_arch_hardware_unsetup(); out_free_0a:

Activate Virtualization On Demand

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